Wheel mounting assembly

Abstract

A wheel mounting assembly for a towed implement which permits vertical movement of a casterwheel, adjustment of the level of the implement above the terrain and also serves to return the implement to the desired height after vertical displacement thereof. The assembly includes a casterwheel, pivotally mounted in a caster bracket, which bracket is pantographically linked to an anchor bracket mounted on the implement. The pantographic linkage includes a height adjusting arm, one end of which is pivotally mounted to the caster bracket and the other end of which is pivotally mounted to the anchor bracket. The pantographic linkage also includes a control arm disposed beneath the height adjusting arm which is likewise pivotally mounted to the caster bracket and also to the rear of the implement in parallel relation to the height adjusting arm so as to form a pantographic linkage between the implement and the caster bracket. An adjusting rod extending through the anchor bracket engages the height adjusting arm to permit adjustment of the implement above the terrain. The adjusting rod carries a compression spring which biases the casterwheel downwardly and serves to return the implement to the desired height as the casterwheel moves upwardly upon encountering irregularities in the terrain over which the implement is towed.

What is claimed is: 
     
       1. A wheel mounting assembly for supporting a wheel on a body to permit vertical movement of the wheel relative to the body, pivotal movement of the wheel about a vertical axis and vertical adjustment of the wheel relative to the body, which mounting assembly comprises: a caster which will pivotally receive the wheel and permit its movement about a vertical axis;   a pantographic linkage pivotally attached at one end of the linkage to the caster and adapted to be pivotally attached at the other end to the body, said linkage including first and second arms adapted to be affixed to said body at different vertical points such that said arms are substantially parallel;   an adjusting rod affixed at one end to said first arm and extending therefrom to a bracket for pivoting said first arm about the body to change the position of the body relative to the terrain;   biasing means connected to said adjusting rod biasing the rod and therefore the pantographic linkage downwardly to complement the gravitational force acting on the pantographic linkage; and   means for adjusting the force exerted by said biasing means to cause said pantographic linkage to move through an arc and thereby cause vertical movement of the body relative to the wheel.   
     
     
       2. The assembly of claim 1 wherein said bracket defines a passageway for accommodating said adjusting arm and wherein said biasing means includes: a spring disposed around the end of said adjusting rod extending beyond said passageway and engaging said bracket at one end thereof; and   a retaining member carried by said rod and adjustable relative thereto to exert force on said spring by compression of the spring between the retaining member and the bracket.   
     
     
       3. A casterwheel assembly for a towed implement which assembly will mount a casterwheel and comprises: a caster bracket for pivotally supporting the casterwheel;   a height adjusting arm linking said caster bracket to said implement, one end of said arm being pivotally mounted to said implement and the other end of said arm being pivotally mounted to said caster bracket;   a control arm also linking said caster bracket to said implement, one end of said control arm being pivotally mounted to said caster bracket and the other end of said control arm being pivotally mounted to said implement, said control arm and said height adjusting arm being disposed in substantially parallel relation to form a pantographic linkage between said implement and said caster bracket; and   adjustment means affixed at one end to said height adjusting arm, and being adjustable relative to said implement, the adjustment of said means capable of changing the position of said implement with respect to the terrain by pivoting said height adjustment arm about the rear of said implement thereby changing the position of the implement relative to the casterwheel.   
     
     
       4. The casterwheel assembly as defined in claim 3 wherein said adjustment means includes a moveable rod rigidly connected to said height adjusting arm, said rod capable of being adjusted to pivot said arm about said implement to change the position of said implement relative to said casterwheel. 
     
     
       5. The casterwheel assembly defined in claim 3 wherein said rod is spring cushioned to absorb vibration imparted to the assembly as it traverses irregularities in the terrain and biased to cause the casterwheel to return to its preset position thereafter. 
     
     
       6. A casterwheel assembly for a towed implement adapted to permit vertical adjustment of the casterwheel over a continuous range of heights, comprising: a caster bracket for supporting the casterwheel;   an anchor bracket rigidly mounted to said implement;   a height adjusting arm linking said caster bracket to said implement, one end of said arm pivotally mounted to said anchor bracket, the other end of said arm pivotally mounted to said caster bracket, said arm also having a shoe extending from the lower surface thereof to facilitate the leveraging of said arm about said anchor bracket;   
     
     
       a control arm linking said caster bracket to said implement, one end of said control bracket pivotally mounted to said caster bracket, the other end of said control bracket pivotally mounted to said implement; said control arm and said height adjusting arm being disposed in substantially parallel relation to form a pantographic linkage between said implement and said caster brackets;   an adjusting rod having a sleeve disposed along the outer end thereof, said rod extending through said anchor bracket substantially parallel to the surface of said implement to engage said shoe such that movement of said rod with respect to said anchor bracket causes said height adjusting arm to pivot about said anchor bracket to change the position of the implement above the terrain;   a compression spring disposed about said rod between said anchor bracket and said sleeve for absorbing vibration imparted to said assembly by said rod as the casterwheel traverses irregularities in the terrain; and   bolting means threadedly disposed about the outer end of the said rod and cooperating with said spring to maintain said rod against said height adjusting arm with constant force to cause the casterwheel to return to its preset position thereafter.